Boris Johnson retreated into a fridge as he sought to avoid a TV interview, amid rattled nerves at CCHQ over a narrowing in the opinion polls.

The prime minister was ambushed by the Good Morning Britain producer, Jonathan Swain, during a pre-dawn visit to Modern Milkman, a business in the Tory-held constituency of Pudsey, in Yorkshire.

When Swain first approached Johnson, he asked: “Morning prime minister, would you come on Good Morning Britain, prime minister?” Johnson’s aide can be heard mouthing “oh for fuck’s sake” in response.

The show’s hosts, Piers Morgan and Susanna Reid, appeared shocked by the aide’s reaction. Swain goes on to say: “I’ve just had a reaction from one of the minders. OK, no need to push, thank you very much,” with Reid exclaiming: “The look on his face, that minder.” The aide was then named on air as the PM’s press secretary, Rob Oxley.

When Swain presses the prime minister, stating he was live on the show, Johnson replied “I’ll be with you in a second” and walked off, before Piers exclaims “he’s gone into the fridge”. Johnson walks inside a fridge stacked with milk bottles with his aides. One person can be heard saying: “It’s a bunker.”

Conservative sources subsequently insisted that Johnson was “categorically not hiding” in the fridge, from which Johnson emerged carrying a crate of milk bottles – but instead his aides were taking a moment to prep the PM for a separate, pre-agreed interview.

During the exchange, Swain asked if Johnson would come on the programme and “deliver on your promise to talk to Piers and Susanna. We’re ready to go, we’re live on ITV right now. Prime minister, we have an earpiece in my pocket. You are more than welcome to come on.”

Swain told Morgan and Reid that he was being pushed and shoved by one of the minders. “It’s a very frosty reception we’ve had so far,” Swain said after Johnson disappeared, to which Morgan responds: “That was heroic work.”

Later that day, the Conservatives were accused of fabricating a story about an assault on an adviser to the health secretary, Matt Hancock, which they later conceded had not taken place.

After the visit to the dairy, Johnson delivered a crate of milk to a house in nearby Guiseley, where the homeowner, Mrs Monaghan, appeared delighted to see him. “It’s so nice to meet you prime minister: what are you doing up so early?” she asked.

Johnson will criss-cross the country throughout Wednesday on a series of final campaign stops, visiting Derbyshire, Wales and Essex.